Power distribution systems, such as telephone switching offices in telecommunications systems are often constructed on a large scale to serve many customers. Since telephone communications are essential for most businesses, it is necessary to ensure that telecommunications systems of this nature are highly reliable. To keep telecommunications systems operational in the event of power interruptions, most telecommunications systems typically include a plurality of high-capacity storage batteries to provide electrical power for operating telecommunications equipment whenever power from the conventional power sources becomes unavailable.
In these telecommunications systems, batteries and power converters are usually connected together so that operating telecommunications equipment are supplied with power from a collection of sources. Notwithstanding this, it is desirable to be capable of isolating individual pieces of telecommunications equipment (or small groups thereof) from the power sources in order to perform maintenance and installation activities. It is also desirable to provide overload protection for telecommunications equipment on an individual basis.
Common overload protection devices for telecommunications equipment fall into two categories namely, fused electrical disconnect devices and circuit breakers. Fused electrical disconnect devices are typically connected to a power distribution panel interconnecting the power source supply buss and the load telecommunications equipment and include replaceable fuses that interrupt power when an overload or fault condition exists. When an overload or fault condition occurs and the fuse in the fused electrical disconnect device blows, the fuse must be removed from the fused electrical disconnect device and replaced before current flow to the telecommunications equipment can be resumed. Many variations of fused electrical disconnect devices exist. For example, a fused electrical disconnect device that includes an alarm fuse and a protection fuse is disclosed in U.S. Pat. No. 5,355,274 to Marach et al.
Circuit breakers typically include plug-in type connectors and are plugged into power distribution panels interconnecting load telecommunications equipment and the power source supply buss. Similar to fused electrical disconnect devices, circuit breakers also interrupt power when an overload or fault condition exists but can be manually reset to resume current flow to the telecommunications equipment without requiring the circuit breakers to be removed from the power distribution panels.
The connection interfaces and relative sizes of fused electrical disconnect devices and circuit breakers have, to-date, been radically different. As a result, it has not been possible to install circuit breakers in power distribution systems originally set up for use with fused electrical disconnect devices. The converse has also been true. Thus, switching the type of overload protection devices used in power distribution systems in the past has been costly and time consuming, making it impractical.
It is therefore an object of the present invention to provide a novel fused electrical disconnect device.